**How long would it take to walk across Australia? **

This lesson enables students to jump, walk, and crawl around the world without breaking a sweat. The featured concept of this lesson is computing with scientific notation, but it also involves the distance formula, and measurement. The common unit of centimeters necessitates the use of scientific notation to solve problems that are too large for most calculators to solve.

Initially, students will have to measure and collect data on the length of their steps, jumps, and so on in centimeters. Record these values on the Earth Measure Wkst.doc using scientific notation. They will also need to find the rate that they can perform these tasks in per minute. The worksheet suggests timing the activity for 10 seconds and then multiplying the amount by 6.

Next, using Google Earth’s ruler tool, the students will need to measure the length of great distances across the globe in centimeters. Remind students to make sure the ruler tool is set to “centimeters” and demonstrate how the Google Earth globe can be moved while using the tool. Record the data on the worksheet using scientific notation.

Now that the data is gathered, review the skills needed to complete the worksheet. Make sure the students understand the scientific notation form of writing numbers and demonstrate how to multiply and divide numbers that are written in this form. The previous earth measurements may vary slightly from student to student but it should be apparent if the scientific notation values are incorrect. Explain how using the Distance Formula, D=rt, with the centimeter measures written in scientific notation, these various computations can be accomplished more easily. Calculators should be used to compute the non-powers of 10 portion of the problem, but then students should use simple arithmetic with the exponents to complete the solution. Agree on an amount answers should be rounded to.

Note: There is no Google Earth Kmz download for this lesson. Google Earth is used as a measuring tool. The Earth Measure worksheet includes directions and some instruction; its download is available with the Teacher Downloads above and I provide it to the students on the Lesson Download page. You may want to edit the worksheet to include additional problems, or you may want to have the students write their own problems to share.

Objectives

- Measure distance between two points
- Calculate personal rates of walking, crawling, and jumping
- Express large numbers in scientific notation
- Perform operations with numbers written in scientific notation
- Use the distance formula to solve problems